Can openers

ABSTRACT

A CAN OPENER OF THE TYPE IN WHICH A ROTATABLE CUTTER CUTS THROUGH THE SEAMING WALL OF A DOUBLE END SEAM OF A CAN, THE CUTTER BEING MOUNTED ON A SPINDLE IN A HOUSING WHICH ALSO CARRIES A ROTATABLE TRACTION ROLL TO RUN ALONG THE CAN SEAM DURING CUTTING. THE CUTTER SPINDLE IS MOUNTED AT AN ACUTE ANGLE TO THE TRACTION ROLL AXIS, SUCH THAT THE CUTTER AXIS IS PARALLEL TO A FACE OF THE TRACTION ROLL THAT ENGAGES THE CHUCK OR REAR WALL OF THE CAN SEAM.

M. R. FRENCH CAN OPENERS Filed June 23, 1971 Marh 13, 1973 w m 2 Z W M A, w m F HTTORNlP/S United States Patent 3,719,991 CAN OPENERS Michael Robert French, St. Albans, England, assignor to The Metal Box Company Limited, London, England Filed June 23, 1971, Ser. No. 155,998 Claims priority, application Great Britain, June 24, 1970, 30,610/ 70 Int. Cl. B67b 7/34 US. Cl. 30-15.5 3 Claims ABSTRACT OF THE DISCLOSURE A can opener of the type in which a rotatable cutter cuts through the seaming wall of a double end seam of a can, the cutter being mounted on a spindle in a housing which also carries a rotatable traction roll to run along the can seam during cutting. The cutter spindle is monted at an acute angle to the traction roll axis, such that the cutter axis is aparallel to a face of the traction roll that engages the chuck or rear wall of the can seam.

BACKGROUND OF THE INVENTION (1) Field of the invention This invention relates to can openers of the kind having a rotatable cutter which cuts through the seaming wall of the double seam securing a can end to a can body.

(2) Description of the prior art United States patent specification 3,510,941 (Fyfe), assigned to the assignees of this present application, discloses a can opener of the above type having, in particular, the following features.

(a) A rotatable cutter arranged to cut through the seaming wall of a double end seam by which a can end is secured to a can body;

(b) A traction roll (wheel) having a chuck wall engaging face and a peripheral surface parallel to the axis of the traction roll and arranged to engage a curved portion connecting the seaming and chuck walls of a can end seam;

(c) A cutter spindle with which the cutter is rotatable;

(d) A roll spindle (wheel spindle) with which the traction roll is rotatable,

(e) The cutter spindle is mounted substantially at right angles to the roll spindle;

(f) A common housing in which both said spindles are mounted;

(g) Means associated with one of the spindles to effect rotation thereof;

(h) A first abutment, substantially parallel with the roll spindle and extending from a face of the housing at the trailing end thereof (considered in the direction of movement of the housing during a cutting operation), this abutment being such as to engage the top of the can end seam soas to tilt the housing about the roll spindle when the said peripheral surface of the traction roll is engaged with the top of the can end seam, whereby to determine the dive angle, which for the purposes of the present specification can be defined as the angle between a first plane, parallel to the roll spindle and containing a tangent to the cutting edge of the cutter at the point of first contact between the cutter edge and he can end seam, and a second plane containing the top of the can end seam;

(i) A second abutment on the housing, arranged to engage the side of the can during cutting; and

(j) Means for moving the roll spindle axially to facilitate location of the traction roll and cutter relative to the can end seam.

The present invention is concerned basically with a can 3,719,991 Patented Mar. 13, 1973 Opener having features (s), (i) and (j), and such a can opener will be called herein a can opener of the kind specified.

SUMMARY OF THE INVENTION (1) Purposes of the invention One object of the invention is to provide, in a can opener of the kind specified, means whereby a smaller applied torque need be applied than in the prior art arrangement.

Another object is to enable a traction roll of reduced diameter to be used.

A further object is to provide a better bearing support for the cutter spindle than in the prior art arrangement.

Another object is to increase the bearing surface of the cutter spindle.

A further object is to reduce the end thrust on the lower end of the cutter spindle.

Yet another object is to reduce any tendency of the cutter to tilt during cutting.

A still further object is to facilitate accurate setting of the gap between the traction roll and the cutting edge.

Further objects and features of this invention will become apparent from the following description when read in conjunction with the accompanying drawings.

(2) Brief description of the invention A can opener has a rotatable cutter which cuts through the seaming wall of the double seam securing a can end to a can body. More specifically, the can opener has the nine features specified under (a), (b), (c), (d), (f), (g), (h), (i) and (j) in the section hereinbefore headed Description of the Prior Art.

The can opener has the cutter spindle mounted at an acute angle with respect to the roll spindle, said angle being such that the axis of rotation of the cutter is substantially parallel to the chuck wall engaging face of the traction roll in a plane containing the point of contact between that face and the can seam.

Thus for feature (e) in the opener disclosed in US. specification 3,510,941 there is substituted by the present invention an inclined cutter spindle. Among the consequences of adopting this arrangement are the following:

(1) Increased length becomes available for accommodating that part of the cutter spindle which lies in the housing between the cutter and the roll spindle, because the centre of the cutter is now further from the roll spindle if the cutting edge is spaced by an unchanged amount from the roll spindle. A deeper top bearing surface for the cutter spindle thus becomes possible, and thus a better bearing support than in the prior art arrangement.

(2) Following from (1) above or as an alternative thereto, the invention makes it possible to bring the cutting edge closer to the axis of the roll spindle adjacent the traction roll, so that a traction roll of reduced diameter, in both the chuck wall engaging face and the peripheral surface, can be used. This enables a smaller applied torque to be used.

(3) Since the resultant reaction force on the cutting edge is approximately perpendicular to the chuck Wall engaging face of the roll, this reaction becomes approximately radial with respect to the cutter and so substantially reduces any tendency of the latter to tilt during outing. It also substantially reduces any need for a thrust hearing at the lower end of the cutter spindle.

(4) Accurate setting of the gap between the traction roll and the cutting edge is facilitated, because any end errors associated with the cutter or its spindle will exist parallel to the chuck wall engaging face and will therefore not affect this gap.

The can opener according to the invention may in addition have a buttress surface located between the cutting edge of the cutter and the cutter axis, so as to engage the seam during cutting and to constrain the cutting edge against penetration thereof through a layer of the end seam other than the outer layer. In this case the buttress surface may be frusta-conical.

Can openers according to the invention may be provided with a handle for holding the opener in one hand while the other hand operates the rotating means recited in (g) above; or the handle may be omitted; the opener may be of a wall-mounted or base-mounted type; the rotating means in (g) above may be power operated or manually operated.

BRIEF DESCRIPTION OF THE DRAWINGS DESCRIPTION OF THE PREFERRED EMBODIMENT The drawings show can openers having the following features:

(a) A rotatable cutter arranged to cut through the seaming wall 11 (FIG. 4) of a double end sea-m 12 by which a can end 13 is secured to a can body 14;

(b) A traction roll 15 having a chuck wall engaging face 16 and a peripheral surface 17 parallel to the axis of the traction wall 15 and arranged to engage the top surface 18 of the can seam formed on a curved portion connecting the seaming wall 11 and chuck wall 19 of the end seam 12;

(c) A cutter spindle 20 with which the cutter 10 is rotatable;

(d) A roll spindle 21 with which the traction roll 15 is rotatable;

(f) A common housing 22 in which both spindles 20, 21 are mounted;

(g) A butterfly handle 23 mounted on the roll spindle 21 for rotating the latter manually;

(h) An abutment pin 24, substantially parallel with the roll spindle 21 and extending from a face 25 of the housing 22 at the trailing end of the latter, the pin 24 being such as to engage the top surface 18 (FIGS. 1 and 4) of the can seam so as to tilt the housing 22 about the roll spindle 21 when the traction roll surface 17 is engaged with the seam top surface 18: in this way the dive angle is determined, that is to say the angle D (FIG. 1) between (i) the plane (horizontal in FIGS. 1 and 2), parallel to the roll spindle 21 and containing a tangent 26 to the cutting edge 27 of the cutter 10 at the point 28 of first contact between the cutting edge and the can end seam, and (ii) the plane 18 containing the top of the seam;

(i) An abutment 29 on the housing 22, arranged to engage the side wall 14 of the can during cutting; and

(j) Means within the handle 23, for moving the roll spindle 21 axially to facilitate location of the traction roll 15 and cutter 10 relative to the can end seam 12, said means being disclosed in the aforementioned United States patent specification 3,510,941 and comprising (see FIG. 2) a pin 40 fixed to roll spindle 21 and riding in an angled slot 41 in the central portion 42 of handle 23, the latter being a sliding fit on spindle 21. As described in the aforesaid United States specification, reverse rotation of the handle 23 to the position shown in FIG. 2 causes pin 40 to move in s ot 41 so to draw the traction roll 15 into contact with the end seam 12, this positionbeing shown in FIG. 4.

The cutter spindle 20 is mounted at an acute angle E (FIG. 2) with respect to the roll spindle 21, such that the axis of rotation of the cutter 10 is substantially parallel to the chuck wall engaging face 16 of the traction roll in the plane 30 containing the point of contact between that face 16 and the chuck wall 19 of the seam.

The cutter spindle 20 is rotatable in a simple top bearing 31 and bottom bearing 32 formed in the housing 22. The cutter itself has a fr-usto-conical peripheral face 33 which, at its uppermost point 34 in FIG. 2, is preferably parallel with the axis of the roll spindle 21 and which terminates in the cutting edge-27. Below the edge 27, and between it and the cutter axis, is a frusto-conical buttress surface 35 formed on the cutter and, as seen in FIGS. 2 and 4, perpendicular to the roll spindle axis at the point of can seam. FIG. 4 illustrates how the surface 35 engages the wall 11; it serves to constrain the cutting edge 27 against penetration thereof through more than the outer layer of the seam.

The buttress surface 35 could alternatively be formed on a separate member coaxial with the cutter, or it may be fixed with respect to the housing 22.

The traction roll 15 may be integral with its spindle, but in the embodiment shown it is a separate member, screwed by a self locking thread 36 to the spindle 21. The spindle in this case is of precision ground unhardened steel, the traction roll 15 being of hardened steel. The faces 16 and 17 of the traction roll are serrated.

In a typical example of a can opener as shown in the drawings, the ratio of the diameter of the face 17 of the traction roll to that of the cutting edge 27 is 1/4.

The opener of FIG. 1 is provided with a handle 37 for holding the opener in one hand while the other hand operates the butterfly handle 23. The opener shown in FIG. 3 is without the handle 37 and may have instead a second abutment pin 38, to steady the opener on the can seam during the cutting operation.

It will thus be seen that there is provided a can opener which achieves the various objects of the invention and which is well adapted to meet the conditions of practical use.

As various other possible embodiments may be made of the above invention, and as various changes might be made in the embodiment above set forth, it is to be understood that all matter herein described or showing in the accompanying drawing is to be interpreted as illustrated by way of example, and not in a limiting sense.

I claim:

1. A can opener comprising a housing, a rotatable cutter to cut through the seaming wall of a double end seam by Which a can end is secured to a can body, a cutter spindle mounted in the housing and carrying the cutter, a rotatable traction roll having a chuck Wall engaging face and a peripheral surface parallel to the traction roll axis to engage a cured portion connecting the seaming and chuck walls of a said seam, a roll spindle mounted in the housing and carrying the traction roll, means associated with one of the said spindles to effect rotation thereof, a first abutment parallel with the roll spindle and extending from the trailing end of the housmg so as to engage the top of a said seam whereby to tilt the housing about the roll spindle when said peripheral surface of the traction roll is engaged with the top of said seam, a second abutment on the housing to engage the can side, and means for moving the roll spindle axially to facilitate location of the traction roll and cutter relative to a said seam: characterised in that the cutter spindle is mounted at an acute angle with respect to the roll spindle, said angle being such that the axis of rotation of the cutter is parallel to the chuck Wall engaging face of the traction roll in a plane containing the point of con-= tact between that face and the can se m,

2. A can opener accordng to claim 1, having a buttress surface located between the cutting edge of the cutter and the cutter axis so as to engage a said seam during cutting and to constrain the cutting edge against penetration thereof through a layer of the end seam other than the outer layer.

3. A can opener according to claim 2, wherein said buttress surface is frusto-conical.

References Cited UNITED STATES PATENTS ROBERT C. RIORDON, Primary Examiner G. L. SMITH, Assistant Examiner 

